• 대한방사선방어학회:학술대회논문집
• /
• 대한방사선방어학회 2011년도 추계 학술발표회 및 심포지엄
• /
• pp.266-267
• /
• 2011

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.511-515
• /
• 1996

A remote controlled mobile robot system has been developed and tested to monitor the radiation area in the nuclear power plant. The mobile robot system operates according to car-driving-like commands and is capable of radiation measurement and visual inspection in unmanned situations under radiation. The robot system is equipped with a radiation sensor and two cameras with appropriate illumination set-ups. The camera with auto-focus function and 8-times zoom lens is mounted on the pan/tilt rotational base and the other is mounted on the front panel of the robot system. All commands regarding the motion of the mobile robot and various sensors are given through the monitoring system which is designed to provide an integrated man-machine interface.

• 대한의용생체공학회:의공학회지
• /
• 제38권5호
• /
• pp.256-263
• /
• 2017

By using the buildup characteristics of the radiophotoluminescence glass dosimeter(RPLGD), it is aimed to help the measurement of the accurate dose by measuring the radiation dose according to the time of the glass element. Five glass elements were arranged on the table and the source to image receptor distance(SID) was set to 100 cm for the build-up radiation dose measurement of the fluorescent glass dosimeter glass element(GD-352M). Radiation doses and saturation rates were measured over time according to irradiation time, with the tube voltage (30, 60, 90 kVp) and tube current (50, 100 mAs) Repeatability test was repeated ten times to measure the coefficient of variation. The radiation dose increased from 0.182 mGy to 12.902 mGy and the saturation rate increased from 58.3% with increasing exposure condition and time. The coefficient of variation of the glass elements of the fluorescent glass dosimeter was ranged from 0.2 to 0.77 according to the X - ray exposure conditions. X - ray exposure showed that the radiation dose and saturation rate were increased with buildup characteristics, and degeneration of glass elements was not observed. The reproducibility of the variation coefficient of the radiation generator was included within the error range and the reproducibility of the radiation dose was excellent.

• 대한방사선치료학회지
• /
• 제5권1호
• /
• pp.131-135
• /
• 1992

• 방사선산업학회지
• /
• 제17권2호
• /
• pp.151-160
• /
• 2023

The International Atomic Energy Agency (IAEA) proposes 11 industries that handle Naturally Occurring Radioactive Material (NORM) that are considered to need management. A water treatment facility is one of the above industries that takes in groundwater and produces drinking water through a water treatment process. Groundwater can accumulate natural radionuclides such as uranium and thorium in raw water by contacting rocks or soil containing natural radionuclides. Therefore, there is a possibility that workers in water treatment facilities will be exposed due to the accumulation of natural radionuclides in the water treatment process. The goal of this study is to evaluate the external radiation dose according to the working type of workers in water treatment facilities. In order to achieve the above goal, the study was conducted by dividing it into 1) analysis of the exposure environment, 2) measurement of the external radiation dose rate 3) evaluation of the external radiation dose. In the stage of analyzing the exposure environment, major processes that are expected to occur significantly were derived. In the measurement stage of the external radiation dose rate, a map of the external radiation dose rate was prepared by measuring the spatial radiation dose rate in major processes. Through this, detailed measurement points were selected considering the movement of workers. In the external radiation dose evaluation stage, the external radiation dose was evaluated based on the previously derived external radiation dose rate and working time. As a result of measuring the external radiation dose rate at the detailed points of water treatment facilities A to C, it was 1.90×10^-1 to 3.75×10⁰ μSv h^-1, and the external radiation dose was analyzed as 3.27×10^-3 to 9.85×10^-2 mSv y^-1. The maximum external radiation dose appeared during the disinfection and cleaning of activated carbon at facility B, and it is judged that natural radionuclides were concentrated in activated carbon. It was found that the external radiation dose of workers in the water treatment facility was less than 1mSv y^-1, which is about 10% of the dose limit for the public. As a result of this study, it was found that the radiological effect of external radiation dose of domestic water treatment facility workers was insignificant. The results are expected to contribute as background data to present optimized safety management measures for domestic NORM industries in the future.

• 한국의학물리학회지:의학물리
• /
• 제29권4호
• /
• pp.123-136
• /
• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• Journal of Radiation Protection and Research
• /
• 제44권2호
• /
• pp.79-88
• /
• 2019

Background: The main goal of experiments is to compare various operational and technical characteristics of D-Shuttle semiconductor personal dosimeters of the Japanese company "Chiyoda Technol Corporation" and Harshaw thermoluminescent dosimeters (TLD) manufactured by "Thermo Fisher Scientific" and DTL-02 of the Russian Research and Production Enterprise (RPE) "Doza" by their occupational and calibration exposure at various dose equivalents from 0.5 to 20 mSv of gamma-radiation. Materials and Methods: Besides dosimeters DTL-02, D-Shuttle and Harshaw TLD, there were also used: (1) the primary reference radionuclide source Hopewell Designs IAEA: G10-1-12 with $^{137}Cs$ isotope (an error is not more than 6% and activity is 20 Ci), and (2) the verification device UPGD-2M of RPE "Doza" and installed in the National Center for Expertise and Certification of the Republic of Kazakhstan (Kapchagai, the National Center for Expertise and Certification). Results and Discussion: The main results of researches are the following: (1) TLDs for Harshaw 6600 and DVG-02TM have an approximately equal measurement accuracy of the individual dose equivalents in the range from 0.5 to 20 mSv of gamma-radiation. (2) Advantages of dosimeters for Harshaw 6600 are due to the high measurement productivity and opportunity to indicate the dose on the skin $H_p$(0.07). Advantages of DVG-02TM consist of operation simplicity and lower cost than of Harshaw 6600. (3) D-Shuttles are convenient for use in the current and the operational monitoring of ionizing radiation. Measurement accuracy and 10% linearity of measurements are ensured when D-Shuttle is irradiated with dose equivalents below 1 mSv at the equivalent dose rate not higher than $3mSv{\cdot}hr^{-1}$. This allows using D-Shuttle at a routine technological activity. Conclusion: The obtained results of experiments demonstrate advantages and disadvantages of D-Shuttle semiconductor dosimeters in comparison with two TLD systems of DVG-02TM and Harshaw 6600.

• 대한방사선치료학회지
• /
• 제16권1호
• /
• pp.57-65
• /
• 2004

서론 : 폐암환자의 방사선치료계획 시 불균질 조직 보정(inhomogeneity correction)을 평가하기 위해 폐(lung), (bone) 그리고 뼈를 고정시키기 위해 사용하는 고밀도 물질인 steel 등을 포함한 불균질 조직 보정 팬텀(inhomogeneity correction phantom, ICP)을 자체 제작하였다. 이를 이용하여 방사선치료계획시스템에서 불균질조직 보정 알고리듬에 따른 값들을 비교하고, 또한 실제 측정된 값과 비교, 분석하여 불균질 조직에 따른 선량계산 변화를 평가하고자 하였다. 대상 및 방법 : 영상획득은 전산화단층촬영영상장치(CT, Volume zoom, Germany)와 자체 제작한 불균질 조직 보정팬텀(ICP, pig's vertebra, steel(8.21 g/cm3), cork(0.23 g/cm3))을 사용하였다. 방사선치료계획시스템으로는 Marks Plan(2D)과 XiO(CMS, USA, 3D)를 사용하였고, 측정값과의 비교를 위해서는 선형가속기(CL/1800, Varian, USA)와 이온전리함을 사용하였다. 전산화단층촬영영상장치로부터 획득한 영상을 이용하여 방사선치료계획장치에서 관심점(interest point, IP)에서의 점선량(point dose)과 선량분포를 얻고, 이와 동일한 조건에서 측정을 수행한 후 비교, 분석하였다. 그리고 불균질 조직 보정 알고리듬 사용 유무에 따른 차이와 방사선치료계획장치가 가지고 있는 다양한 불균질 조직 보정 알고리듬 간의 차이도 비교하였다. 결 과 : 불균질 조직 보정 팬텀 내 관심지점에 대한 측정치와 방사선치료계획장치에서 얻은 균질과 불균질 보정된 값을 비교한 결과 폐 제1지점에서의 측정치와 불균질 보정값의 오차는 2D에서 $0.8\%$, 3D에서 $0.5\%$, 스틸 제1지점에서의 측정치와 불균질 보정값의 오차는 2D에서 $12\%$, 3D에서 $5\%$의 오차를 보이나 보정을 하지 않은 값과 측정치의 오차는 각각 $16\%,\;14\%$의 오차가 나는 것을 알 수 있었다. 또한 2D에서 보다는 3D에서의 값들이 오차가 적은 것으로 나타났다. 결 론 : 방사선치료계획 시 조직 내 밀도에 따른 보정이 반드시 이루어져야 하며 보다 정확한 치료계획을 위해서는 2차원 방사선치료계획용 시스템보다는 3차원 방사선치료계획용 시스템을 사용하는 것이 정확한 보정이 가능한 것을 알 수 있었다. 그리고 불균질 조직 보정 알고리듬 간에도 차이가 있어 실제 측정을 통해 가장 적합한 불균질 조직 보정 알고리듬을 선택하는 것이 필수적이라 할 수 있다. 향후 열형광선량계와 필름 선량계를 통한 비교, 분석이 추가적으로 수행되어야 할 것으로 사료된다.

• Journal of Radiation Protection and Research
• /
• 제40권3호
• /
• pp.174-180
• /
• 2015

예비 방사선 작업 종사자인 방사선학과 대학생을 대상으로 방사선 기초 개념과 공간선량 인식, 방사선 안전 인식에 대해 알아보고자 하였다. X선 촬영 실습실에서 X선 조사 시 발생하는 공간선량을 학생들이 직접 측정함으로써 방사선 기초 개념과 공간선량 인식에 따른 실험 전 후의 방사선 안전 인식 변화를 파악하고자 하였다. 그 결과 실험 후에 학생들의 방사선 안전 인식이 보수적이고 엄격하게 변화하는 것을 알 수 있었다. 그럼에도 불구하고 방사선학과 대학생들의 경우 방사선 안전 인식 보다 직업의식이 앞서는 형태를 볼 수 있었는데 이는 의료적 이용에 따른 이득을 우선적으로 고려한 결과로 생각된다. 이에 따라 의료적 이익의 범위 내에서 방사선 이용에 따른 세분화된 안전교육 프로그램이 필요성이 요구된다. 따라서 시청각 자료를 이용한 단순한 강의 중심의 안전 교육이 아닌, 직접 공간선량 측정 실험과 같은 체험적 안전 교육 프로그램을 제안하는 바이며 방사선 안전 인식의 보수적인 관점과 엄격한 태도를 지향하는 직업의식 교육이 필요한 것으로 파악되었다.

• Radiation Oncology Journal
• /
• 제32권1호
• /
• pp.43-47
• /
• 2014

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.